Sensitivity Analysis And Optimization Of Suspension Performance For Four Wheel Independent Drive Electric Vehicle

Having many advantages, four wheel independent drive electric vehicle is a newresearch direction of electric vehicle. At the same time, due to the introduction of thehub motor which increased the unsprung mass, the vehicle handling stability and ridecomfort suffered a performance loss. The sensitivity analysis and optimization ofvehicle suspension characteristics contributed in improving vehicle manipulationstability and ride comfort performance..This dissertation is based on the project of China Postdoctoral Fund named“Research on Intergraded Chassis Control Strategy of Drive-by-wire Electric Vehiclewith Four Wheels Independent Control”. The main research content of thisdissertation was focused on the handling stability and ride comfort of the four wheelindependent drive electric vehicle and aimed at a suspensionperformance optimization. In order to achieve this objective, the simulation of hubmotor vehicles to install which performances was affected by the method ofsensitivity analysis, and according to the affected properties to optimize thesuspension properties.The main contents of this dissertation were as follows:(1) The establishment of a joint simulation of vehicle modelA vehicle model was built by Carsim software and an electric drive componentmodel was built by Matlab/Simulink. Using the method of cooperation simulation,models of traditional vehicle and the four wheel independent drive electric vehiclemodel were built, laying the foundation for the follow-up study.(2) The test between traditional vehicle and four wheel independent drive vehicleWith considerations based on vehicle handling stability and ride comfort,simulation experiments were carried out between traditional vehicle and four wheelindependent drive vehicle. On-center conditions, angle step condition, double lane change conditions, high and low return conditions, random road input conditions andconvex block input condition were studied. Through a series of experiments，theeffect of vehicle with in hub motor were obtained, and some phenomena wereanalyzed as well.(3) Four wheel electric vehicle suspension performance sensitivity independentlydriven analysisAfter analyzed the impact of vehicle with in wheel motor by the iSight softwareusing orthogonal Latin hypercube method, sensitivity analysis was carried out on fourwheel independent drive electric vehicle suspension parameters. From the manyparameters selected parameters has great effect on the performance, laying thefoundation for optimization of the work follow-up.(4) four wheel electric vehicle suspension performance independently drivenmulti objective optimizationBased on parameter sensitivity of each index, software of iSight was used,operated an optimization method for multi targets for four wheel independent driveelectric vehicle suspension parameters using particle swarm method. After determinedthe objective function and the parameters of optimization, the optimization of fourwheel electric vehicle suspension independent drive solution was obtained. Applyingthe parameters to the vehicle model, the handling stability and ride comfort wereimproved to a certain degree.